USN-4367-1: Linux kernel vulnerabilities

Releases

• Ubuntu 20.04 LTS

Packages

• linux - Linux kernel
• linux-aws - Linux kernel for Amazon Web Services (AWS) systems
• linux-azure - Linux kernel for Microsoft Azure Cloud systems
• linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
• linux-kvm - Linux kernel for cloud environments
• linux-oracle - Linux kernel for Oracle Cloud systems
• linux-raspi - Linux kernel for Raspberry Pi (V8) systems
• linux-riscv - Linux kernel for RISC-V systems

Details

It was discovered that the btrfs implementation in the Linux kernel did not
properly detect that a block was marked dirty in some situations. An
attacker could use this to specially craft a file system image that, when
unmounted, could cause a denial of service (system crash). (CVE-2019-19377)

It was discovered that the linux kernel did not properly validate certain
mount options to the tmpfs virtual memory file system. A local attacker
with the ability to specify mount options could use this to cause a denial
of service (system crash). (CVE-2020-11565)

It was discovered that the block layer in the Linux kernel contained a race
condition leading to a use-after-free vulnerability. A local attacker could
possibly use this to cause a denial of service (system crash) or execute
arbitrary code. (CVE-2020-12657)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 20.04

• linux-image-5.4.0-1011-aws - 5.4.0-1011.11
• linux-image-5.4.0-1011-gcp - 5.4.0-1011.11
• linux-image-5.4.0-1011-kvm - 5.4.0-1011.11
• linux-image-5.4.0-1011-oracle - 5.4.0-1011.11
• linux-image-5.4.0-1011-raspi - 5.4.0-1011.11
• linux-image-5.4.0-1012-azure - 5.4.0-1012.12
• linux-image-5.4.0-26-generic - 5.4.0-26.30
• linux-image-5.4.0-31-generic - 5.4.0-31.35
• linux-image-5.4.0-31-generic-lpae - 5.4.0-31.35
• linux-image-5.4.0-31-lowlatency - 5.4.0-31.35
• linux-image-aws - 5.4.0.1011.14
• linux-image-azure - 5.4.0.1012.14
• linux-image-gcp - 5.4.0.1011.12
• linux-image-generic - 5.4.0.31.36
• linux-image-generic-lpae - 5.4.0.31.36
• linux-image-gke - 5.4.0.1011.12
• linux-image-kvm - 5.4.0.1011.12
• linux-image-lowlatency - 5.4.0.31.36
• linux-image-oem - 5.4.0.31.36
• linux-image-oem-osp1 - 5.4.0.31.36
• linux-image-oracle - 5.4.0.1011.12
• linux-image-raspi - 5.4.0.1011.11
• linux-image-raspi2 - 5.4.0.1011.11
• linux-image-virtual - 5.4.0.31.36

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References

• CVE-2019-19377
• CVE-2020-11565
• CVE-2020-12657
• CVE-2020-12826

Related notices

• USN-4369-1: linux-image-5.3.0-53-generic-lpae, linux-image-gcp, linux-aws-5.3, linux-azure-5.3, linux-image-gke, linux-image-gke-5.3, linux-image-snapdragon-hwe-18.04-edge, linux-image-snapdragon-hwe-18.04, linux-image-5.3.0-1017-kvm, linux-image-generic-hwe-18.04-edge, linux-image-oracle-edge, linux, linux-image-lowlatency, linux-image-lowlatency-hwe-18.04-edge, linux-image-azure, linux-oracle-5.3, linux-image-lowlatency-hwe-18.04, linux-image-5.3.0-1020-gcp, linux-image-azure-edge, linux-image-virtual-hwe-18.04-edge, linux-oracle, linux-image-generic, linux-image-virtual-hwe-18.04, linux-image-5.3.0-53-snapdragon, linux-image-generic-lpae, linux-image-5.3.0-53-lowlatency, linux-image-5.3.0-1022-azure, linux-azure, linux-gcp-5.3, linux-gke-5.3, linux-image-snapdragon, linux-image-5.3.0-1020-gke, linux-image-aws-edge, linux-image-aws, linux-image-gkeop-5.3, linux-image-raspi2, linux-image-kvm, linux-gcp, linux-aws, linux-image-5.3.0-1018-oracle, linux-image-generic-hwe-18.04, linux-image-5.3.0-53-generic, linux-image-oracle, linux-hwe, linux-image-generic-lpae-hwe-18.04, linux-image-gcp-edge, linux-raspi2, linux-image-virtual, linux-image-generic-lpae-hwe-18.04-edge, linux-kvm, linux-image-5.3.0-1019-aws, linux-image-5.3.0-1025-raspi2
• USN-4414-1: linux-image-lowlatency-hwe-16.04-edge, linux-image-oracle-lts-18.04, linux-image-gcp, linux-image-gcp-lts-18.04, linux-snapdragon, linux-gcp-4.15, linux-image-gke, linux-azure-4.15, linux, linux-image-lowlatency, linux-image-azure, linux-image-virtual-hwe-16.04-edge, linux-image-4.15.0-1078-gcp, linux-kvm, linux-image-azure-edge, linux-oracle, linux-image-generic, linux-image-4.15.0-109-lowlatency, linux-image-4.15.0-109-generic, linux-image-4.15.0-1046-oracle, linux-image-4.15.0-1069-kvm, linux-image-4.15.0-1091-oem, linux-image-virtual-hwe-16.04, linux-image-4.15.0-107-lowlatency, linux-image-aws-hwe, linux-image-generic-lpae, linux-image-4.15.0-1048-oracle, linux-image-generic-lpae-hwe-16.04, linux-image-oem, linux-azure, linux-image-4.15.0-1077-aws, linux-image-snapdragon, linux-image-aws-lts-18.04, linux-image-lowlatency-hwe-16.04, linux-image-generic-hwe-16.04, linux-oem, linux-aws-hwe, linux-image-4.15.0-1074-aws, linux-image-4.15.0-107-generic-lpae, linux-image-raspi2, linux-image-azure-lts-18.04, linux-image-kvm, linux-gcp, linux-gke-4.15, linux-aws, linux-image-4.15.0-107-generic, linux-image-4.15.0-1065-raspi2, linux-image-4.15.0-1081-snapdragon, linux-image-generic-lpae-hwe-16.04-edge, linux-image-oracle, linux-hwe, linux-raspi2, linux-image-4.15.0-109-generic-lpae, linux-image-generic-hwe-16.04-edge, linux-image-virtual, linux-image-gke-4.15, linux-image-4.15.0-1064-gke, linux-image-4.15.0-1091-azure
• USN-4364-1: linux-image-generic-lts-utopic, linux-image-generic-lts-xenial, linux-image-4.4.0-1133-raspi2, linux-image-4.4.0-179-generic, linux-image-4.4.0-179-powerpc64-smp, linux-snapdragon, linux-image-virtual-lts-wily, linux-image-4.4.0-179-powerpc-e500mc, linux-image-generic-lts-vivid, linux, linux-image-lowlatency, linux-image-generic-lts-wily, linux-image-powerpc64-emb-lts-vivid, linux-image-powerpc-e500mc, linux-image-virtual-lts-utopic, linux-image-generic-lpae-lts-utopic, linux-image-powerpc64-emb-lts-wily, linux-image-generic-lpae-lts-xenial, linux-kvm, linux-image-4.4.0-179-lowlatency, linux-image-generic, linux-image-powerpc-e500mc-lts-wily, linux-image-4.4.0-1107-aws, linux-image-lowlatency-lts-xenial, linux-image-powerpc64-emb, linux-image-powerpc64-emb-lts-utopic, linux-image-powerpc-smp-lts-xenial, linux-image-powerpc-smp-lts-wily, linux-image-generic-lpae, linux-image-4.4.0-179-powerpc-smp, linux-image-4.4.0-1137-snapdragon, linux-image-4.4.0-1071-kvm, linux-image-snapdragon, linux-image-4.4.0-179-powerpc64-emb, linux-image-lowlatency-lts-wily, linux-image-powerpc-e500mc-lts-vivid, linux-lts-xenial, linux-image-generic-lpae-lts-vivid, linux-image-aws, linux-image-lowlatency-lts-utopic, linux-image-raspi2, linux-image-powerpc64-smp-lts-vivid, linux-image-powerpc-e500mc-lts-utopic, linux-image-kvm, linux-image-powerpc-smp-lts-vivid, linux-image-powerpc64-smp-lts-wily, linux-aws, linux-image-powerpc64-smp, linux-image-lowlatency-lts-vivid, linux-image-powerpc-e500mc-lts-xenial, linux-image-virtual-lts-xenial, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc-smp, linux-image-generic-lpae-lts-wily, linux-raspi2, linux-image-4.4.0-179-generic-lpae, linux-image-4.4.0-1067-aws, linux-image-virtual, linux-image-powerpc64-emb-lts-xenial, linux-image-virtual-lts-vivid, linux-image-powerpc-smp-lts-utopic, linux-image-powerpc64-smp-lts-utopic
• USN-4363-1: linux-image-lowlatency-hwe-16.04-edge, linux-image-oracle-lts-18.04, linux-image-gcp, linux-snapdragon, linux-image-4.15.0-1059-gke, linux-image-gke, linux-image-4.15.0-101-generic, linux-azure-4.15, linux, linux-image-lowlatency, linux-image-4.15.0-1067-aws, linux-image-azure, linux-image-virtual-hwe-16.04-edge, linux-kvm, linux-image-azure-edge, linux-oracle, linux-image-generic, linux-image-4.15.0-1060-kvm, linux-image-virtual-hwe-16.04, linux-image-aws-hwe, linux-image-generic-lpae, linux-image-oem, linux-image-generic-lpae-hwe-16.04, linux-azure, linux-image-snapdragon, linux-image-aws-lts-18.04, linux-image-lowlatency-hwe-16.04, linux-image-generic-hwe-16.04, linux-oem, linux-aws-hwe, linux-image-4.15.0-101-generic-lpae, linux-image-4.15.0-1081-oem, linux-image-raspi2, linux-image-azure-lts-18.04, linux-image-4.15.0-1039-oracle, linux-gcp, linux-gke-4.15, linux-image-kvm, linux-aws, linux-image-4.15.0-1083-azure, linux-image-4.15.0-1079-snapdragon, linux-image-generic-lpae-hwe-16.04-edge, linux-image-4.15.0-1071-gcp, linux-image-oracle, linux-hwe, linux-raspi2, linux-image-4.15.0-1062-raspi2, linux-image-generic-hwe-16.04-edge, linux-image-virtual, linux-image-gke-4.15, linux-image-4.15.0-101-lowlatency
• USN-4368-1: linux-image-gke-5.0, linux-image-5.0.0-1037-gke, linux-image-oem-osp1, linux-oem-osp1, linux-gke-5.0, linux-image-5.0.0-1052-oem-osp1
• USN-4391-1: linux-image-generic-lts-utopic, linux-image-generic-lts-xenial, linux-image-4.4.0-184-powerpc-smp, linux-image-4.4.0-184-generic, linux-snapdragon, linux-image-4.4.0-184-powerpc-e500mc, linux-image-virtual-lts-wily, linux-image-4.4.0-184-lowlatency, linux-image-generic-lts-vivid, linux-image-4.4.0-1073-aws, linux, linux-image-lowlatency, linux-image-generic-lts-wily, linux-image-powerpc64-emb-lts-vivid, linux-image-powerpc-e500mc, linux-image-virtual-lts-utopic, linux-image-generic-lpae-lts-utopic, linux-image-powerpc64-emb-lts-wily, linux-image-generic-lpae-lts-xenial, linux-kvm, linux-image-generic, linux-image-4.4.0-1075-kvm, linux-image-powerpc-e500mc-lts-wily, linux-image-lowlatency-lts-xenial, linux-image-4.4.0-184-powerpc64-smp, linux-image-4.4.0-184-powerpc64-emb, linux-image-powerpc64-emb, linux-image-powerpc-smp-lts-xenial, linux-image-powerpc-smp-lts-wily, linux-image-powerpc64-emb-lts-utopic, linux-image-4.4.0-1134-raspi2, linux-image-generic-lpae, linux-image-snapdragon, linux-image-lowlatency-lts-wily, linux-image-powerpc-e500mc-lts-vivid, linux-lts-xenial, linux-image-generic-lpae-lts-vivid, linux-image-aws, linux-image-lowlatency-lts-utopic, linux-image-raspi2, linux-image-4.4.0-184-generic-lpae, linux-image-powerpc-e500mc-lts-utopic, linux-image-kvm, linux-image-powerpc-smp-lts-vivid, linux-image-powerpc64-smp-lts-vivid, linux-image-powerpc64-smp-lts-wily, linux-aws, linux-image-powerpc64-smp, linux-image-lowlatency-lts-vivid, linux-image-powerpc-e500mc-lts-xenial, linux-image-virtual-lts-xenial, linux-image-powerpc64-smp-lts-xenial, linux-image-powerpc-smp, linux-image-generic-lpae-lts-wily, linux-image-4.4.0-1109-aws, linux-raspi2, linux-image-4.4.0-1138-snapdragon, linux-image-virtual, linux-image-virtual-lts-vivid, linux-image-powerpc64-emb-lts-xenial, linux-image-powerpc-smp-lts-utopic, linux-image-powerpc64-smp-lts-utopic